Amid a flurry of Q4 13F filings, a few notable observations have emerged.

First, after unwinding his modest Amazon stake in the quarter ended December 31, George Soros’s family office, Soros Fund Management, added 2.47 million shares of Overstock or 9.9% of the outstanding stock worth $158MM, making him the third largest holder of the innovative online retailer. One wonders if Soros is becoming a believer in blockchain and bitcoin-supporting online vendors?

That aside, Soros was busy in Q4: in the quarter, in addition to his new position in OSTK, Soros started new positions in the following companies: KW, TGT, FG, GPS, PLAY, HAL, ZAYO. At the same time, Soros exited the recently hammered TEVA as well as RLGY, CPN, EQT, S, CIEIQ, LOXO, HUN. The family office boosted its stakes NXPI, CZR, HZNP, MON, COL, KMDA, TWX while cutting its positions in MNK, AGN, SGYP, DISH, TMUS, VST, SHPG, XCRA.

A snapshot of Soros’ Top 25 positions and changes over the quarter is shown below, with new positions shaded in green.

Yet while Soros was exiting his Teva stake, none other than Warren Buffett was buying.

According to Berkshire’s 13F, Buffett dumped most of his IBM shares, holding only 2 million shares at the end of 2017, down 90% from the end of Q3. At the same time he added to Apple, and on Dec. 31, 2017, Berkshire boosted its stake in Apple to 165 million shares, a 23% increase in the quarter, and equivalent to about $28 billion. The purchase cements Buffett as Apple’s 4th largest shareholer, behind State Street with 206 million shares.

But the one position that has caught the media’s attention is Berkshire’s new investment in generic drugmaker Teva, which has been battered in recent months, and whose shares soared as much as 12% after hours on the news of Buffett’s investment. Another reason for Teva’s bounce: Jana confirmed a stake in the struggling pharmaceutical company, suggesting an activist campaign is imminent.

As a reminder, last month Berkshire, along with JPM and Amazon, said that it was planning to start a health-care company. The effort is still in its early stages and few details have emerged, but the three companies have said the new venture will be “free from profit-making incentives and constraints.” The initial focus will be to use technology to improve coverage and reduce costs for their hundreds of thousands of employees. News of the effort sent health-care stocks plunging. It is unclear if Teva will play any role in this strategic vision.

Meanwhile, as Bloomberg highlights, many prominent hedge funds exited some key FAANG stocks in Q4 before the stocks saw some weakness in the last months of the year.

Some details from Bloomberg:

Philippe Laffont’s Coatue Management, which rode the FAANG wave last year, sold 2.84 million shares of Apple Inc., bringing the value of its holding to $730 million as of Dec. 31. In September, Laffont called the new iPhone X “groundbreaking” but its sales have since disappointed. The firm also reduced its Facebook Inc. position by 1.71 million shares, according to regulatory filings Wednesday.